The flat bed trailer or truck having a plurality of stake pockets along its periphery is well known. For example, U.S. Pat. No. 4,453,761, to Felburn discloses such a trailer in its FIG. 2, where stake pockets are shown as item 11. As noted by Felburn, the common practice is to space such stake pockets two feet apart center to center. These pockets are sized to accept stakes, said stakes being used to hold panels, typically plywood panels in place along the side of the trailer.
A smooth peripheral surface to the trailer is provided by a side rail or rub rail which is welded across the outward side of the stake pockets, typically parallel to the bed of the trailer.
In many trailers today, it is common practice to construct as many components of the trailer of aluminum and other lightweight metals, so as to reduce the weight of the trailer, thereby allowing larger load sizes and better fuel economy. When a relatively soft metal such as aluminum is used, the trailer, the stake pockets, and the side or rub rail are all subject to disfigurement and distortion due to any collision with foreign objects. Particularly, it is common practice to unload such flat bed trailers by removing one or more sections of panels and driving a tow motor or other similar implement upon the bed of the trailer from an adjacent dock. In doing so, it is not unusual for the unloading implement to strike the side of the trailer, the stake pockets, or the rubrail, resulting in damage thereto.